I think that even before Biden's brain processing unit was scrambled eggs he didn't actually believe in anything. I would describe it less as a mindset and more as a "mode." To the extent that he pretends to believe in anything, it's to weaponize it for class interests. You can see this in those old clips where he remarks about "prostituting" himself to lobbyists in his 20s, or saying that "if Israel didn't exist we'd have to invent it" (the subtext being, to protect US imperial interests in the Levant). So when he appeals to those evangelicals obsessed with the holy land, it's less because he was ideologically captured by the spectacle of the gulf war, and more because he was part of the class of people who helped make it happen.

Even with Russia, it's less that he really believes Putin is building USSR2 (even though he said that at the beginning of the war) and more that he wants to secure a market for US liquid natural gas by using Ukraine as a bulwark against the potential development of a friendship between the Russian bourgeoisie and the western/middle European bourgeoisie. Because before that war started he admitted wanting to destroy Nordstream. So even in that scrambled brain of his, the class interests hiding behind the culture war posturing still sometimes leaps out.